Calm down. With brains and application, the British-Irish relationship will surmount the problems of Brexit

The letter from 200 northern nationalists saying that Brexit leaves them with a similar sense of abandonment to their parents or grandparents after partition makes depressing reading.

Has it really come to this?

If proof is needed, the evidence of damage caused by Brexit is paraded before our eyes after the briefest moment of euphoria that we’d got over a big hump.

But Nationalists are not unique.

Brexit has excited real fears on both sides.

If you close your eyes and let your worst feelings rip without restraint, both sets are all too plausible.

This is what happens in a chronic leadership vacuum.

There is a risk that clever people may make fears worse.

Extreme views of an Irish “rights” constitution against a British “political” constitution could bring the two into conflict and wreck the GFA.

Nationalists may exaggerate the power of Irish/EU citizenship in Northern Ireland to hold out for Sinn Fein’s claims of right, under which they seem to mean that nationalists must get anything they voted for, regardless of the political process.

This conjures up a vision of Irish citizens living in an alien land that is the Brexit North, a large minority with their rights guaranteed and brokered by an outside government and an international court and with little more than a nod to the transactional nature of the democratic institutions in Stormont and London from which the main nationalist party absents itself.

On the other hand, unionists claim that British majoritarianism and a sovereign parliament must win out (for now) and nationalists will have to lump it. This applies not only to imposing the majority UK decision to withdraw from the EU and quit the single market and the customs union over the local Remain majority. It extends actively in the teeth of opposition beyond nationalism to considering an amnesty for former members of the security forces alone, a hot topic that hitherto had been part of a comprehensive consultation.

This way lies madness.

Like the rival players in the Old Trafford tunnel, everybody should calm down.

I would like to know from petitioners such as the lawyers Patricia Lundy and Colin Harvey what rights under the GFA would be infringed by any Brexit outcome.

On the unionist side, it’s surely obvious that the pressure for change of constitutional status will begin from within, from the north, rather than from the south, from Leo Varadkar and Micheal Martin.

Both leaders have shown far more sensitivity over Brexit and the North than the British.

The Northern Ireland Secretary James Brokenshire has yet again displayed his surely wilful incomprehension of the divided community of which he is currently the only governor. At least the stumbling David Davis has tried to answer his Irish critics and offer assurances of a mutually satisfactorily outcome. This should not be dismissed.

The petitioners should be consoled by the fact that Ireland’s interests will continued to be upheld in a separate strand of the trade talks.

But nobody on the EU side in the end can force the British to remain within the single market or the customs union. That relationship will be decided for better or worse, at Westminster. Beyond that as a formality, Northern Ireland’s position seems all to play for.

Rather than rely on an appeal to Varadkar to deliver more than he’s able, the petitioners might join him in insisting that Sinn Fein return to the Executive. That would give them something in common with the DUP and the wider unionist community, whom they have to live with and cannot pretend don’t exist.

And rather than appear to write off the GFA, they should insist that the two governments operate it far more actively, even from opposite sides of the Brexit table.

The British-Irish relationship is bigger than Brexit. Our parents and grandparents never enjoyed such advantages. But it is the solemn responsibilty of the two governments to care for its good health and above all, to avoid mimicking the chronic division of the main northern parties which now looks like infecting the whole of society.